In rolling mills and strip treatment plants, sheet metal and strips are dried after processing. Press rollers are used for the preliminary cleaning of sheet metal and strips. It has also already been attempted to remove remaining liquid residues by means of compressed air.
DE 28 44 434 A1 discloses a method for suctioning liquid residues from continuously traveling sheet metal and strips, particularly in rolling mills and strip treatment plants, in which in a defined area suction air flows produced by a negative pressure of at least 0.4 bar are guided transversely over the top side of the sheet metal and the bottom side of the sheet metal, and the absorbed liquid is separated from the suction air.
Moreover, in drying, and in keeping strips dry, particularly rolled strips, it is known to separate the dry area of the finished rolled hot strip from the moist chamber of the roll stand by means of bulkheads. In accordance with DE 199 08 743 A1, a contactless seal is produced between the bulkhead and the rolled strip by an aircushion-like compressed air padding as well as a split flow, for which purpose pressurized gas from a plurality of nozzles is directed from the top and bottom onto the strip surfaces and at a right angle onto the strip surfaces.
On the other hand, new types of steel have been marketed in recent years. Even though some of these steel qualities are distinguished by a particular deformability, the principal attention is directed to an increase of the achievable strength. For this purpose, plans of attack are available. By a rapid and targeted cooling of the strip by means of a guide cooling sections, a high strength can be achieved and simultaneously the rolling train can be relieved. For this purpose, however, usually low reel temperatures are necessary, which leads to difficulties during cooling, during coiling and particularly during further processing.
Strips from numerous types of steel newly developed in recent years, for example, of dual phase steel, martensite phase steel or QT-Steel (Q=quenched, T=tempered), are cooled following a hot strip train on a runout roller table directly or with a cooling interruption to relatively low temperatures, for example, in the range of between 25 and 400 degrees C., and are then coiled moist onto the coiler. A complete evaporation of the water is not possible within the coil produced by coiling. As a result, the strips are subjected to a greater oxidation. During long dwell times of the coil up to further processing, the pickling agent can no longer remove the rust from the surface. A direct further processing is not always possible which is a disadvantage with respect to quality as well as flexibility.